1. Field of the Invention
This invention relates to a polymeric composition. More particularly, this invention relates to a thermoplastic elastomer composition.
2. Prior Art
Thermoplastic elastomer compositions are, of course, well known in the prior art. One type of thermoplastic elastomer compositions comprises a crystalline polyolefin and a cured or at least partially cured elastomer as taught, for example, in U.S. Pat. Nos. 3,037,954; 3,758,643; 4,104,210 and 4,130,535 and in "Thermoplastic Elastomers--A Comprehensive Review", N. R. Legge et al., particularly Chapter 7 thereof, Munich, Germany, Hanser Publishers, 1987. In general, the thermoplastic elastomer compositions known in the prior art and/or articles fabricated therewith are said to exhibit excellent mechanical and dynamic properties, particularly high tensile strength, good toughness and good elongation. The thermoplastic elastomer compositions are useful for making a variety of articles by extrusion, injection molding, compression molding and the like. Molded articles prepared with these thermoplastic elastomer compositions, however, exhibit relatively low service temperatures-softening and becoming subject to distortion at relatively low temperatures. As a result, articles fabricated with the thermoplastic elastomer compositions known in the prior art often cannot be used in locations where elevated temperatures are experienced such as "under-the-hood" of an automobile operated with an internal combustion engine or the like.
It is of course known that articles for high temperature service can be fabricated from nylon, particularly nylon 6. Nylon is, however, difficult to mold and must be dried before molding. Moreover, nylon will become brittle if too dry. Nylon also has a relatively high specific gravity thereby requiring an increased weight of polymer to prepare any given structure. In light of the deficiency of the thermoplastic elastomeric composition heretofore known, and the difficulties encountered when nylon is used, the need for an improved polymer composition which can be conveniently used to mold articles for high temperature service is believed to be readily apparent.